Trim covers of a vehicle seat are each constituted of multiple outer cover materials joined to one another. Further, so as to prevent floating of a seat outer cover and to improve design characteristics, inward hanging is conducted along edge portions of the outer cover materials constituting the trim covers of the seat. FIG. 7 and FIG. 8 show a conventional example, where FIG. 7 is a partial cross-sectional view of a transitional area between a seating face 51 and a bank face 53, and FIGS. 8(a) and 8(b) are schematic views of lateral inward hanging ends 60 viewed from an obverse surface side. In case of adoption of multiple outer cover materials, inward hanging is to be conducted along stitching edges (sewing edges) of the outer covers, in such a manner shown in FIG. 7 to embed an insert wire 54 into a cushion material, and to engage inward hanging cords attached to sewing edge portions of the outer cover materials with the insert wire by clips, C-rings, or the like.
Further, it is typical to contemplate further improving an external appearance quality, by combiningly using: longitudinal inward hanging to be conducted between the seating face 51 and the bank face 53; and lateral inward hanging to be conducted for the seating face 51, in a direction orthogonal to the bank face 53; (see Patent Document 1, for example, cited below).
However, as shown in FIG. 7, each lateral inward hanging end 60 which corresponds to a longitudinal/lateral inward hanging intersection, and a lower end (not shown) of the bank which is located at an end of the longitudinal inward hanging, are sites where inward hanging is terminated, so that outer cover excesses are likely to be caused there, such as due to partially lowered tensions of pulling in, and a failure of compliance of outer covers with three-dimensional shapes at the inward hanging ends, respectively.
Namely, as shown in the schematic views of the lateral inward hanging ends 60 viewed from the obverse surface side thereof in FIGS. 8(a) and 8(b), the outer cover excesses caused at the lateral inward hanging ends 60 bring about deteriorated external appearance qualities at the inward hanging ends, such as deflections 55, creases 56, and the like of the outer covers.
Inherently, to avoid outer cover excesses, it is required to conduct inward hanging in a manner that the edges of the outer covers to be sewn together have the same lengths as the edges themselves such that the outer covers are pulled in by the inward hanging. However, it is then very likely that a sewing operation is not allowed in case of trim covers for which a pulled-in feeling of inward hanging is demanded, because the sewing margins of those portions corresponding to the longitudinal/lateral inward hanging intersections become complicated three-dimensional shapes then, respectively. Further, inward hanging lines at the trim cover side are then disadvantageously deflected, upon mounting thereof onto a cushion material.
As such, it has been conventionally contemplated to adjust the shapes of the inward hanging margins, the sewing margins, and the like on a pattern paper for cutting out workpieces for the outer cover materials at the time of fabrication of the pattern paper, so as to enable sewing and to avoid occurrence of deflections of the outer covers at inward hanging ends thereof.
However, even in case of such contemplation, edges of the outer covers to be sewn together are always configured to have lengths longer than those of the edges themselves such that the outer covers are pulled in by the inward hanging. Thus, such an insufficiency of balance brings about occurrence of the deflections 55 of the inward hanging lines, the creases 56, and the like.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-95093.